Theoretical study of gallium nitride nanocage as a carrier for 5-fluorouracil anticancer drug

In this paper, the possible interactions between 5-fluorouracil (5FU) as an anticancer drug and gallium nitride (Ga12N12) nanocage (NC) in aqueous solution have been investigated using DFT/CPCM/B3LYP-D/6-31G(d,p) level of theory. Eleven different orientations were used to mimic the 5FU adsorbed on Ga12N12 (5FU@GaNNC). To investigate the interaction mechanism between the two components, the adsorption energies and thermodynamic parameters, the electronic properties such as the energies and orbitals distribution of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), the HOMO-LUMO energy gaps (Eg), the density of states (DOS), partial DOS (PDOS), and the molecular electrostatic potential (MEP) have been calculated and compared. The natural bond orbitals (NBOs) and the quantum theory of atoms in molecules (QTAIM) calculations have been applied for understanding chemical interactions and chemical bonding. Additionally, some quantum molecular descriptors were calculated for the understanding of molecular reactivity. Main results revealed that (1) the key factor that leads to stabilization of the formed complex/s is the relocation of one of the H atoms that originally belonging to one of the N atoms in 5FU to one of the nearest Ga atoms in GaNNC and (2) the adsorption energies for the eleven adsorbed systems are relatively larger compared with reported similar systems indicating from a theoretical point of view, a probable chemisorption type of adsorption and the privilege of GaNNC as a carrier for 5FU drug.